In key win for GSK, Delaware court will review decision to allow expert testimony in Zantac cases

Twelve days after GSK secured a key win in Florida, with a state court tossing expert testimony on the cancer-causing potential of heartburn drug Zantac (ranitidine), the British company has scored a similar but possibly more impactful victory.

The Delaware Supreme Court has upheld a GSK appeal, deciding to review the state’s Superior Court decision to allow expert testimony that would support 75,000 personal injury Zantac lawsuits that have been consolidated in the state. 

The review has potentially enormous consequences. In June, when a Delaware Superior Court judge allowed the lawsuits to proceed, ruling that juries in the state could hear expert testimony about the health risks with Zantac, analysts at ODDO BHF estimated that GSK faced potential exposure of $2 billion if the company pursued a wide-ranging settlement.

But, if the review favors GSK, it “could be dispositive for some or all” of the claims filed in Delaware, Justice N. Christopher Griffiths wrote in Tuesday’s Supreme Court order. In addition, potentially benefiting from the review are Pfizer and Sanofi, which also are defending certain Zantac lawsuits that have been consolidated in Delaware.

With Tuesday’s decision to perform a review, GSK’s shares rose by 4%.

“The scientific consensus remains that there is no consistent or reliable evidence that ranitidine increases the risk of any cancer,” GSK said in a statement. “Since 2019, there are 16 epidemiological studies looking at human data regarding the use of ranitidine, including outcomes for more than 1 million patients using ranitidine, supporting this consensus.”

The state Supreme Court ruling doesn’t immediately affect litigation of the 75,000 cases, which will proceed in parallel with the review. According to the Supreme Court order, litigation is underway on two tracks. One addresses whether the use of Zantac's original active ingredient, ranitidine, can cause cancer. The other is focused on discovery and identifying bellwether cases to take to early trials.

On the first track, plaintiffs have retained 10 experts to offer their opinions on whether ranitidine can cause the 10 different cancers named in the cases.

The Delaware Superior Court’s ruling in June was termed a “Daubert decision,” referring to a 1993 U.S. Supreme Court case that provides criteria for determining whether expert testimony is admissible under a federal evidence rule, GSK explained.

“In applying the Daubert standard, the Court acts as a gatekeeper, ensuring that expert opinions meet certain standards for reliability and that speculative or unreliable opinions are not presented to the jury,” the company noted.

GSK is among several companies facing lawsuits that claim Zantac—which was developed by GSK and approved in 1983—can cause cancer. Sanofi acquired the then-over-the-counter treatment in a 2016 asset swap with Boehringer Ingelheim and then pulled Zantac off the market in 2019 when an online pharmacy, Valisure, raised questions about its contents.

In 2020, the FDA instructed all companies to take Zantac off the market after it confirmed that the compound’s main ingredient ranitidine can transform into a possible carcinogen over time or when exposed to high temperatures. Zantac has since returned to the market with a new formulation that does not include ranitidine.

Companies facing federal litigation, including Pfizer, gained a huge win in 2022 when a Florida district judge rejected the science backing the claims that Zantac can cause cancer. The ruling freed the drugmakers from approximately 50,000 cases that had been consolidated in the Florida court.